Relationship
Combo chart
- Relationship
What it shows
Columns and a line on shared or dual axes.
When to use it
Use it when
Showing a volume alongside a rate, such as sales and margin.
Avoid it when
Two scales would confuse the message.
When to use it
Use a combination chart for related measures with a common category or time axis, such as orders and an average order value.
Worked example
Across three months, show order count as columns and average order value as a line. If using two scales, label both explicitly and check for a misleading visual alignment.
Data required
Consistent time buckets, well-defined measures, appropriate aggregation and named units for every series.
Checks and common mistakes
Do not stack incompatible units or let an arbitrary secondary-axis range imply correlation. Test a separated-panel version for clarity.
More accessible alternative
Use separate aligned panels if the measures have different scales or the combined visual becomes crowded.